| Nanomaterials have attracted much attention in the past decade due to their surface effect, small size effect and quantum tunnel effect. Gold nanorods(GNRs), one of typical gold nanomaterials, were widely used in sensor, imaging, drug loading and catalysis. This thesis mainly focused on the fabrication of chem/bio-sensor based on the localized surface plasmon resonance(LSPR) properties of GNRs, and the proposed sensors were used to analyze biological samples. The main research contents in thesis are listed as follows:(1) Under proper conditions, Fe3+, Hg2+, Cu2+, and Ag+ ions can react with GNRs, resulting in changes of nanostructure and composition. The sensor for determination of these metal ions is therefore established accompainied by the changes of longitudinal plasmon wavelength of nanorods. This GNR-based assay can not only determine all four kinds of metal ions successively but also detect which of any one or several kinds of metal ions. This assay is sensitive to detect Fe3+, Hg2+, Cu2+, and Ag+ as low as 10-6, 10-9, 10-10, and 10-8 M, respectively. Importantly, the special nanostructure and composition of the nanorods induced by these metal ions allow this sensor to maintain high selectivity to determine these metal ions.(2) An analytical strategy for determination of Cu2+ is developed based on the formation of core-shell gold nanorods resulted from the reactions among Cu2+, Na2S2O3, Hg2+, Na BH4 and GNRs. The assay is of very high sensitivity and can determine trace amount of copper as low as 1 f M. The practical biological samples including human serum, urine, and red blood cells were analyzed, and the copper levels of these samples are 20.67 μM, 0.193 μM and 3.09 × 10-16 g in a single cell. This label free, ultrasensitive and selectivive approach has potential application for determination the copper level of a single cell after the optimal conditional experiment.(3) A promising combined assay for the successive detection of blood glucose and serum copper level based on etching of gold nanorods was developed. A hydroxyl radical-enhanced GNR oxidation under ultraviolet irradiation facilitates the establishment of a plasmonic biosensor that may quickly detect blood glucose with limit of detection(LOD) 0.45 m M. Subsquently, a blue-shift of the longitudinal plasmon wavelength induced by various forms of copper in the presence of Na2S2O3 may be performed, providing a sensitive approach to detect the total copper level in a biological sample. A combined assay for the successive detection of the blood glucose level and serum copper was therefore developed, which possess great potential applications for successively monitoring blood glucose and copper concentrations during the progressof diabetes.(4) An integration strategy for diagnosis, co-delivery drugs and treatment of breast cancer based on multifunctional GNRs is developed. Firstly, a combined detection of cancer antigen 15-3 and bio-copper in serum of breast cancer was established, which provide an assay to monitor bio-markers in the progress of breast cancer. Applications to analyze serum samples of breast cancer demonstrate these results were close agreement with the results given by the hospital. Secondly, a platform to load and co-delivery two kinds of drugs conjugated on the same GNRs was fabricated, on which the doxorubicin hydrochloride(DOX) and DNA were loaded by covalent bonding and physics adsorption, respectively. Moreover, further selective release of drugs may be triggered by chemical and near infrared(NIR) laser. Thirdly, an alternately controlled release two drugs inside MCF-7 cells based on single type of GNRs was successfully achieved by tuning the parameters of chemical reaction and NIR laser irradiation. This study does provide a novel nano-platform for possible integration of multi-functionality including combined diagnosis, drugs co-delivery, chemotherapy as well as photothermal therapy, which can potentially lead to improved cancer monitoring and therapeutic efficacy. |
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